The present invention relates in general to rail vehicle drives and in particular to a new and useful dual gimbal coupling provided between a hollow shaft and a rail vehicle axis going through it and consisting of a hollow, stub-shaped, intermediate shaft enclosing the axle with clearance. The invention includes elastic and articulated couplings disposed at the ends of the intermediate shaft, the mutually facing coupling halves containing a common hub in the form of the intermediate shaft and the outer coupling halves having hubs suited to the hollow shaft or the axle. Each of the couplings has arms which emanate from their hubs and lie, alternating one behind the other, in a common plane perpendicular to the shafts, there being disposed at the end of each arm, two shaft-parallel bolts juxtaposed in the direction of rotation, from which bolts emanates a spherically movable connecting rod to the adjacent arms, at least at one of the coupling sides.
A coupling of similar type is known from German OS No. 27 16 115. However, it is a characteristic there that the connecting rods, which are fishplate-like and interconnect two neighboring bolts of the interacting coupling halves, are rigid in themselves. The power is transmitted between the connecting rods and the bolts through spherically designed rubber bearings permitting a spherical deflection of the connecting rods. The limits of the deflectability are determined by the rubber layer of these spherical bearings. Since the rubber layer is relatively thin and the drive moment must be transmitted as circumferential force, the possible angular deflection is limited. Added to this is the fact that, due to the small rubber mass, the return forces increase out of proportion to the angular deflection.